Metal oxide inverse opals that exhibit three-dimensionally ordered macroporous structures are interesting for various applications. The conventional synthesis route of metal oxide inverse opals is based on structure replication following a colloidal crystal templating process. In the present work, the successful utilization of colloidal crystal templating method to fabricate various metal oxide inverse opals including CeO2, Cr2O3, CuO, Fe2O3, Ga2O3, In2O3, SnO2, TiO2, WO3 and ZnO is reported. Different types of precursors and processing conditions are investigated to optimize their optical reflectance. Another part of this work focus on the optical sensing based on the synthesized WO3 inverse opals. Change of effective refractive index of WO3 inverse opals will cause a shift of their reflection peak position. In this thesis, this shift is evaluated as an optical sensor signal to detect fluids and water temperature. In addition, a series of WO3 inverse opals with different photonic band gap positions are used as optical H2 sensor. The optical responses (H2 induced reflection peak shift) of different WO3 inverse opals are examined to reconstruct the strong refractive index dispersion of WO3 after H2 exposure. This study aimed to find the physical origin of the refractive index change during gas sensing. Then, by gaining the insights into the physical sensing mechanisms, the general rules of the design of optical gas sensor based on metal oxide inverse opals are concluded.